This invention relates to particulate porous materials which contain discrete internal cavities and, more particularly but not exclusively, is concerned with such materials which are suitable for use as column packing materials or supports for enzymes, whole cells or biological polymers, and with a process for preparing the same.
Mullite is an aluminosilicate material which exists in the form of needle-shaped crystals: it has a variable chemical composition but is generally represented by the formula 3Al.sub.2 O.sub.3 .multidot.2SiO.sub.2. Although mullite occurs naturally, it is usually obtained by heating bauxite with clay or sillimanite. It is presently used as a refractory.